Compacting Device for a Spinning Machine

ABSTRACT

The invention relates to a compacting device, comprising two suction drums ( 17 ), wherein a suction drum ( 17 ) in each case is associatable with a pair of delivery rollers ( 7, 8 ) of drafting unit ( 2 ) of a spinning machine, wherein the pair of delivery rollers ( 7, 8 ) is made up of a bottom delivery roller ( 7 ) and a top delivery roller ( 8 ); wherein the suction drums ( 17 ) are rotatably supported, via a bearing, on a shaft that is fastened to a carrier element ( 41 ); wherein a suction channel ( 31 ) extends within the carrier element ( 41 ), and wherein the suction drums ( 17 ) each have a drive element ( 40 ) which in the operating position forms a drive connection with the bottom delivery roller ( 7 ). The invention is characterized in that a protective shield ( 42 ) for preventing lap formation is situated on the axle ( 19 ) of the clamping rollers ( 18 ). The invention further relates to a protective shield ( 42 ) and a corresponding textile machine.

TECHNICAL FIELD

The invention relates to a compacting device for two adjacently situateddrafting units of a spinning machine according to the preamble of theindependent claim, and a textile machine that is equipped with acompacting device.

PRIOR ART

Numerous designs are already known in practice, wherein for compactingthe fiber material (fiber strand) discharged by a drafting unit, acompacting unit is situated downstream. Following such a compactingunit, the compacted fiber material, after passing through a clampingpoint, is fed to a twist generator. Such a twist generator in a ringspinning machine, for example, is composed of a traveler which revolveson a ring, and the yarn produced is wound onto a rotating bobbin.Suctioned revolving, perforated suction drums or revolving apronsprovided with perforations are essentially used as compacting units. Aspecialized suction area on the compacting element is thus defined byusing appropriate inserts inside the suction drum or inside therevolving apron. These types of inserts may be provided, for example,with appropriately shaped suction slits to which a negative pressure isapplied, thus generating a corresponding air flow at the periphery ofthe particular compacting element. In particular, protruding fibers areincorporated as a result of this air flow, which is oriented essentiallytransversely with respect to the direction of transport.

In the known approaches, the fiber material delivered by the draftingunit is guided above or below the compacting devices used. In particularfor use on a ring spinning machine, it is necessary to provide anadditional clamping point downstream from the suction zone in order toobtain a twist stop.

Such types of devices have been illustrated and described in thepublications EP 947614 B1, DE 102005010903 A1, DE 19846268 C2, EP1612309 B1, DE 10018480 A1, and CN 1712588 A, for example. These citedpublications essentially involve compacting units which are installedfollowing the particular drafting system. The drive of these compactingunits is sometimes achieved via specialized drive shafts which aresituated over the length of the spinning machine and which are in driveconnection with either a suction roller or a revolving apron, or via afixedly installed drive connection to appropriately situated pressurerollers of the compacting device.

In practice, it is necessary to retrofit existing spinning machines witha conventional drafting unit having such a compacting device in order toensure the possibility of producing high-quality yarns for thesemachines as well. Therefore, devices have been proposed by means ofwhich conventional drafting systems may be retrofitted with such acompacting device. One such example is found in DE 102 27 463 C1, forexample, in which the punch of the drafting unit is extended in order tosupport an additional drive roller. The drive roller, which extends overthe entire length of the spinning machine, is provided for the drive ofthe retrofitted compacting device. The mounting and installation of sucha retrofit unit is very time-consuming and inflexible; i.e., a desireddismantling to a standard drafting system without a compacting device isin turn very time-consuming.

Published DE 10050089 A1 discloses an embodiment of a compacting devicethat is provided for retrofitting on a conventional drafting unit.

A device is known from CN 2851298 Y in which a compacting rollertogether with a twist stop roller are accommodated in a bearing elementwhich is connected by means of a plate to a pivotable weighting arm of adrafting system device via screws. In the installed and locked position,the drive is transmitted via friction from a delivery roller connecteddirectly to a drive and its associated pressure roller to the compactingroller and the twist stop roller. The compacting device disclosed hereis likewise provided for retrofitting on existing drafting units ofspinning machines without compaction. The mounting of the compactingunit disclosed therein on an existing drafting unit via a screwconnection, as well as the threading for the axle of the pressureroller, is relatively time-consuming, and requires additional adjustmentof the distances. In addition, the connection to a negative pressuresource must also be established separately.

In the designs described above, the suction elements associated with adefined compacting area for compressing the fiber material are acted onby negative pressure via additionally mounted lines that are connectedto a negative pressure source.

In order to simplify such compacting devices by making it possible toeasily and quickly install conventional drafting units without having toinstall additional drive elements, WO 2012/068692 A1 proposes a designin which the compacting element in the form of a suction drum and theclamping roller are rotationally supported on a carrier element. Thecarrier element is detachably mounted to the spinning machine viafastening means. To establish a drive connection between the draftingsystem rollers and the detachably mounted compacting device, thecompacting device is swiveled about a swivel axis in the direction ofthe pair of delivery rollers of the drafting system via the carrierelement, wherein in each case a friction wheel that is coaxiallyfastened to the particular suction drum is frictionally connected (viafriction) to the bottom roller of the pair of delivery rollers of thedrafting system. The compacting device is held in this drive connectionvia appropriately arranged spring elements (for example, on theweighting arm of the drafting system). For a more flexible design forthe drive of the compacting device, WO 2012/068692 A1 further proposesto provide a second gearing stage between the drive element of thecompacting element of the first gearing stage and the compactingelement. One disadvantage of this embodiment, however, is that lapformation sometimes occurs on the clamp axle of the nip roller.

DESCRIPTION OF THE INVENTION

The object of the invention is to simplify and improve the compactingdevices for two adjacently situated drafting units, known from WO2012/068692 A1, in order to prevent lap formation on the axle of theclamping roller.

In particular, this object is achieved by a compacting device accordingto the preamble of the independent claim, which is characterized in thata protective shield for preventing lap formation is situated on the axleof the clamping rollers.

The protective shield may advantageously be made up of two protectiveelements situated on both sides of the bearing, between the particularclamping roller and the middle bearing. The two protective elements mayhave a U-shape and may be connected to one another via at least one web.They may be detachably connected to the clamping roller. The protectiveshield may thus be easily fastened to the clamping roller and removedfor cleaning purposes, for example. The two protective elements may beconnected to one another via two webs, wherein the geometry of the websensures on the one hand anti-twist protection of the protective shieldon the clamping roller, and on the other hand that the protective shieldcan be detachably fastened to the clamping roller in only one way. Lapformation on the clamping roller may be advantageously prevented as aresult of this simple embodiment.

The object is further achieved by a protective shield for preventing lapformation on the axle of the clamping rollers of a compacting device,wherein the protective shield is detachably fastenable to the clampingaxle. The protective shield may be made up of two U-shaped protectiveelements that are detachably fastenable to the axle of the clampingrollers and connected to one another via a web. The protective shieldmay advantageously be made of plastic, with a design of the twoprotective elements as a hollow profile. The protective shield may bemanufactured by injection molding.

The above-mentioned object is further achieved by a textile machineaccording to the preamble of the independent textile machine claim,which is characterized in that a protective shield for preventing lapformation is situated on the axle of the clamping rollers.

Further advantages of the invention will become apparent from oneexemplary embodiment, which is described and illustrated below.

BRIEF DESCRIPTION OF THE FIGURES

The invention is explained in greater detail with reference to theappended figures, in which:

FIG. 1 shows a schematic side view of a drafting system having a carrierelement according to the invention;

FIG. 2 shows a top view of a compacting device according to theinvention, having a protective shield on the shaft of the clamping axle;and

FIG. 3 shows a protective shield according to the present invention.

Only those features that are essential to the invention are illustrated.Identical features are denoted by the same reference numerals in thevarious figures.

APPROACHES FOR CARRYING OUT THE INVENTION

FIG. 1 shows a schematic side view of a spinning station 1 of a spinningmachine (ring spinning machine), having a drafting unit 2 which isprovided with a pair of feed rollers 3, 4, a pair of middle rollers 5,6, and a pair of delivery rollers 7, 8. An apron 12, 13 is guided aroundthe middle rollers 5, 6, respectively, each of which is held in itsillustrated position around a cage, not shown in greater detail. The toprollers 4, 6, 8 of the mentioned roller pairs are designed as pressurerollers that are rotatably supported on a pivotably supported pressurearm 10 via the axles 4 a, 6 a, 8 a, respectively. Two adjacent draftingunits 2 (twin drafting system) are associated with a pressure arm 10.The pressure arm 10 is supported so as to be pivotable about an axle 15,and, as schematically illustrated, is acted on by a spring element 9.This spring element may also be an air hose, for example. The rollers 4,6, 8 are pressed against the bottom rollers 3, 5, and 7, respectively,of the roller pairs via the schematically shown spring loading. Theroller pairs 3, 5, 7 are driven via a drive, not shown. Individualdrives as well as other forms of drives (gearwheels, toothed belts,etc.) may be used. The pressure rollers 4, 6, 8 are driven via thedriven bottom rollers 3, 5, 7, respectively, and the apron 13 is drivenvia the apron 12, by friction. The peripheral speed of the driven roller5 is slightly greater than the peripheral speed of the driven roller 3,so that the fiber material 11 in the form of a sliver fed to thedrafting unit 2 is subjected to a break draft between the pair of feedrollers 3, 4 and the pair of middle rollers 5, 6. The main draft of thefiber material 11 results between the middle roller pair 5, 6 and thepair of delivery rollers 7, 8, the delivery roller 7 having asignificantly higher peripheral speed than the middle roller 5.

The drafted fiber material 11 delivered by the particular pair ofdelivery rollers 7, 8 is deflected downwardly and passes into the areaof a suction zone 16 of a subsequent suction drum 17, which is part ofthe compacting device according to the invention. The particular suctiondrum 17 is provided with perforations or openings 39 extending on itsperiphery. Following the suction zone 16, for each of the suction drums17 a clamping roller 18 is provided which rests on the respectivesuction drum 17 via a pressure load and which with this suction drumforms a clamping line. The particular clamping roller 18 is rotatablysupported on an axle 19 which is held in a guide slot 20 of a U-shapedreceptacle in a pressure arm 21. The axle 19 is displaceably supportedwithin the guide slot 20, transversely with respect to its longitudinalaxis. A tappet that rests on the outer circumference of the axle 19 andis acted on by a schematically indicated compression spring 22 protrudesinto the guide slot 20 through an opening in the pressure arm 21. Theopening is provided approximately centrally at the end of the guide slot20, and opens into an essentially closed cavity in the pressure arm 21in which the compression spring 22 is situated. The compression springis supported on the closed end of the cavity, and with its opposite endrests on a head of the tappet.

The pressure arm 21 is supported so as to be pivotable about an axis ina bearing element that is mounted on the end of the pressure arm. Inthis pivot position, the axes are held at the end of particular guidevia a stop edge, schematically shown in FIG. 1, transverse to theirswivel axis. The clamping rollers 18 rotatably supported on the pressurearm 21 are then loaded against the particular suction drum 17 via theforce of the compression spring 22, thus forming the clamping line. Thepressure arm 21 is pivoted past dead center until it rests on a stop. Inthis position, the axle 19 of the clamping rollers 18 is situated belowthe plane that extends through the swivel axis and the center axis ofthe suction drums 17; i.e., the clamping roller 33 is held in thisposition past top dead center. Further details with regard to themounting and design of the clamping rollers 18 may be found in CH705308.

The pressure lever 10 is subsequently pivoted about its swivel axis 15from an upper position, indicated by dashed lines, into a lower positionin which a pressure force is exerted on the compacting device in thedirection of the roller 7 via a leaf spring 24, fastened to the pressurelever 10 by means of screws 23, and the web 25 that is fastened to theleaf spring. The suction drum 17 thus connected is driven by the roller7 by means of friction via a drive element 40, described below.

In this “operating position,” the warped fiber material 11 that isdelivered by the drafting system 2 is supplied to the subsequent suctionzone 16 of the particular suction drum 17, and compacted in a knownmanner under the influence of the generated suction air flow. Adeflection shield situated at a distance, as illustrated and describedin DE 4426249, for example, may be mounted above the suction zone 16.The cited publication also describes the process for compacting thefiber material.

For generating the required negative pressure in the area of the suctionzone 16, a negative pressure source 26 is provided which is connected toa central suction channel 27. The suction channel 27 is connected via aline 28 and a flexible coupling element 29 to the respective end of thesuction channel 31 of the compacting device that protrudes in thedirection of the suction channel 27. The pivotability of the compactingdevice about an axis 30 is facilitated by the flexibility of thecoupling element 29. The schematically shown coupling element 29 may bedesigned on its outer circumference in such a way that when twohalf-shells are joined together, the coupling element is connected in aform-fit manner to a formed suction channel 31, with tight sealing withrespect to the outside. The design and composition of the half-shells insuch a carrier element are known from WO 2012/068692 A1. The spinningmachine may be advantageously retrofitted with the compacting device.

At the same time, the clamping line created by the clamping roller 18forms a so-called “twist stop gap” from which the fiber material 11, inthe form of a compressed yarn 32, is fed in the conveying direction to aschematically shown ring spinning device. The ring spinning device isprovided with a ring 33 and a traveler 34, the yarn being wound onto abobbin 35 to form a spool 36 (cop). A thread guide 37 is situatedbetween the clamping line and the traveler 34. The ring 33 is fastenedto a ring frame 38 that undergoes an up-and-down motion during thespinning process.

FIG. 2 shows a top view of a compacting device according to theinvention, having a protective shield 42 on the shaft on the axle 19 ofthe clamping rollers 18, and FIG. 3 shows the protective shield 42 in anisolated illustration. The protective shield 42 is made up of twoprotective elements 43 situated on both sides of the bearing/guide slot20, between the particular clamping roller 18 and the middle bearing 20.The two protective elements 43 have a U-shape and are connected to oneanother via two webs 44. The geometry of the webs 44 ensures on the onehand anti-twist protection of the protective shield 42 on the clampingroller 18, and on the other hand, that the protective shield 42 can bedetachably fastened to the clamping roller in only one way. The twoprotective elements 43 are detachably connected to the axle 19 of theclamping roller 18. The protective shield 42 may thus be easily fastenedto the axle 19 and removed for cleaning purposes or replacement, forexample. The two protective elements 43 may be designed as a hollowprofile, which allows simple, cost-effective manufacture. The protectiveshield may be made of plastic, and manufactured by injection molding. Asa result of this embodiment according to the invention, lap formationdue to accumulation of fiber material may be advantageously preventedduring operation by means of the protective shield 42 on the axle 19 ofthe clamping rollers 18.

LIST OF REFERENCE NUMERALS

-   1 spinning station-   2 drafting unit-   3 bottom feed roller-   4 top feed roller-   4 a axle-   5 bottom middle roller-   6 top middle roller-   6 a axle-   7 bottom delivery roller-   7 a axle-   8 top delivery roller-   8 a axle-   9 spring element-   10 pressure arm-   11 fiber sliver-   12 apron-   13 apron-   14 suction zone-   15 axle-   16 suction zone-   17 suction drum-   18 clamping roller-   19 axle of the clamping rollers 19 [sic; 18]-   20 guide slot/bearing-   21 pressure arm-   22 compression spring-   23 screws-   24 leaf spring-   25 web-   26 negative pressure source-   27 suction channel-   28 line-   29 coupling element-   30 axis-   31 suction channel-   32 yarn-   33 ring-   34 ring traveler-   35 cops-   36 spool-   37 thread guide-   38 ring frame-   39 openings-   40 friction wheel, drive wheel-   41 carrier element-   42 protective shield-   43 protective element of the protective shield 42-   44 web between the protective elements 43

1. A compacting device, comprising two suction drums (17), wherein asuction drum (17) in each case is associatable with a pair of deliveryrollers (7, 8) of a drafting unit (2) of a spinning machine, wherein thepair of delivery rollers (7, 8) is made up of a bottom delivery roller(7) and a top delivery roller (8); wherein the suction drums (17) arerotatably supported, via a bearing, on a shaft that is fastened to acarrier element (41); wherein a suction channel (31) extends within thecarrier element (41), wherein the suction drums (17) each have a driveelement (40) which in the operating position forms a drive connectionwith the bottom delivery roller (7), and wherein on the carrier element(41) two clamping rollers (18) are rotatably supported centrally in abearing (20) on a shared axle (19), wherein for forming a clamping line,each of the clamping rollers (18) rests on the outer circumference ofone of the two suction drums (17) under the action of a spring load,characterized in that a protective shield (42) for preventing lapformation is situated on the axle (19) of the clamping rollers (18).2-15. (canceled)